The proposed study will analyze data from mid childhood to late adolescence to identify modifiable risk factors for violence and to examine the developmental etiology of violence across this period. The application seeks two years of support to complete these analyses using eight waves of data from 808 youth from the Seattle Social Development Project (SSDP) panel. SSDP is a theory-driven developmental epidemiology study of childhood and adolescent risk and protective factors for substance abuse and related health and behavior problems. The gender-balanced, multiethnic urban panel, constituted in 1985 when subjects entered the fifth grade in 18 elementary schools, has been tracked and interviewed through 1993 when subjects were aged 17-18. Included in the data are measures of community, family, school, peer, and individual risk and protective factors for and measures of violent behavior, criminal behavior, gang membership, weapon use, drug use, drug selling, and victimization. Modifiable risk factors will be identified using regression and logistic regression analysis, growth curve analysis, structural equation modeling, and latent transition analysis. Competing etiological/theoretical models of violent behavior will be examined. Ethnic and gender differences in prevalence and etiology will be investigated. Since the dataset is already constituted, this study will provide an unusual opportunity to examine the modifiable risk and protective factors for violence longitudinally across crucial ages. This will provide important developmental information for preventive intervention strategies.